Mix of both to be honest, there are cases when the analytical method is the easiest to bash out and others where the graphical one is the best. Depends on the inequality in question, which is why it's good for you to be familiar with both so that you can confidently attack any question with a wide range of tools and techniques that will allow you to attack the problem in the most efficient way.

(Original post by Zacken)
Mix of both to be honest, there are cases when the analytical method is the easiest to bash out and others where the graphical one is the best. Depends on the inequality in question, which is why it's good for you to be familiar with both so that you can confidently attack any question with a wide range of tools and techniques that will allow you to attack the problem in the most efficient way.